Numerous phosphorescent materials are known to the prior art, such as phosphorescent films used to make traffic signs, advertising signs, Christmas decorations, labels and tags, window displays, arts and crafts, decorative decals, etc. Such phosphorescent materials, as known to those skilled in the art, exhibit the quality or characteristic of phosphorescence which, as is further known to those skilled in the art, is luminescence caused by the absorption of radiation, such as visible light or ultra-violet light, which continues for a noticeable time after these radiations have stopped; this luminescence which occurs in the dark after the phosphorescent material has been exposed to such radiations is commonly referred to as the after-glow.
A major problem associated with typical prior art phosphorescent material or films is that when viewed in visible light, e.g. sunlight, incandescent or fluorescent light, such materials typically are provided in only one color, namely an unattractive or eerie green. Articles, such as those noted above, which may be made from such phosphorescent materials, are typically sold inside of a store illuminated by visible light such as incandescent or fluorescent light or sunlight coming through a window, and hence the articles at the point of purchase are unattractive and without decorative appeal due to their above-noted unattractive or eerie green color. Of course, some colored phosphorescent materials are known to the prior art, but these colored phosphorescent films are created by putting colored filters on the films or by adding colorants, such as various colored pigments, to the films but it has been found that such coloring techniques substantially decrease the after-glow properties and hence cause the products to be substantially worthless or of little value due to their greatly diminished after-glow characteristic.
Accordingly, there exists a need in the phosphorescent material art for phosphorescent film, and process of manufacture therefor, which film is decorative in visible light whereby articles produced from the film will be decorative to the naked eye of the potential purchaser at the point of sale, typically the interior of a store illuminated by visible light, whereby the sale of such articles is enhanced.